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The SQL Server ISNULL() function lets you return an alternative value when an expression is NULL: SELECT ProductName, UnitPrice * (UnitsInStock + ISNULL(UnitsOnOrder, 0)) FROM Products;
3 wrz 2024 · Replaces NULL with the specified replacement value. Transact-SQL syntax conventions. Syntax ISNULL ( check_expression , replacement_value ) Arguments check_expression. The expression to be checked for NULL. check_expression can be of any type. replacement_value. The expression to be returned if check_expression is NULL.
Use the LEN function to check for null or empty values. You can just use LEN(@SomeVarcharParm) > 0. This will return false if the value is NULL, '', or ' '. This is because LEN(NULL) returns NULL and NULL > 0 returns false. Also, LEN(' ') returns 0. See for yourself run:
The ISNULL () function can be used anywhere that the SQL syntax allows for the use of a function but the main use case for this function is in the SELECT list of a SQL query when you want to convert any NULL values being returned to something more descriptive.
In this tutorial, you will learn how to use the SQL Server ISNULL() function to replace NULL with a specified value.
3 wrz 2024 · To determine whether an expression is NULL, use IS NULL or IS NOT NULL instead of comparison operators (such as = or !=). Comparison operators return UNKNOWN when either or both arguments are NULL. Examples
This SQL Server tutorial explains how to use the ISNULL function in SQL Server (Transact-SQL) with syntax and examples. In SQL Server (Transact-SQL), the ISNULL function lets you return an alternative value when an expression is NULL.
